Stupefacient \Stu`pe*fa"cient\, a. [L. stupefaciens, p. pr. of
stupefacere to stupefy; stupere to be stupefied + facere to
make. Cf. {Stupefy}.] [Written also {stupifacient}.]
Producing stupefaction; stupefactive. -- n. (Med.) Anything
promoting stupefaction; a narcotic.
[1913 Webster]